Check These Out
single-column-numbers.txt is a text file with 22658 rows (numbers) in a single column. Each number can range from 0 to 134298679.533591 and the dot is for the decimals.
This is done with perl because awk can't sum such high numbers.
To check if the table-of-content in a LaTeX document is up-to-date, copy it to a backup before running LaTeX and compare the new .toc to the backup. If they are identical, it is updated. If not, you need to run LaTeX again.
Find files that are older than x days in the working directory and list them. This will recurse all the sub-directories inside the working directory.
By changing the value for -mtime, you can adjust the time and by replacing the ls command with, say, rm, you can remove those files if you wish to.
Bash can accept '0x' and '0' notation for hexidecimal and octal numbers, so you just have to output the values.
The above is an example of grabbing only the first column. You can define the start and end points specifically by chacater position using the following command:
$ while read l; do echo ${l:10:40}; done < three-column-list.txt > column-c10-c40.txt
Of course, it doesn't have to be a column, or extraction, it can be replacement
$ while read l; do echo ${l/foo/bar}; done < list-with-foo.txt > list-with-bar.txt
Read more about parameter expansion here:
http://wiki.bash-hackers.org/syntax/pe
Think of this as an alternative to awk or sed for file operations
generates a picture file with the text.
Some other samples in:
http://www.imagemagick.org/Usage/text/
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"
This will search all directories and ignore the CVS ones. Then it will search all files in the resulting directories and act on them.
just set macdst to the mac address of the system
you wish to wake up, the macsrc is optional but helps
use tcpreplay to broadcast or wireshark to view